Renal stone disease: a commentary on the nature and significance of Randall's plaque.

To better understand these three main potential pathways for stone formation [5] , we have produced an illustration ( fig. 1 ) that depicts the site of initial mineralization along the nephron/renal pelvis, and the final location of the developing stone for each pathway. The three pathways are labeled: ‘free-particle’ stone formation, stone formation on a plug (sometimes referred to as the ‘fixed-particle’ model), and Randall’s plaque. In this short paper we will confine our discussion to the Randall’s plaque hypothesis and touch only briefly on the other two theories. To give a historical perspective to Randall’s plaque hypothesis, we will begin by reviewing his original observations and then link them to our own more recent findings.